Draft gear



y 1946- G. E. DAQTH ET AL DRAFT GEAR Filed July 1'7, 1945 Gear ge E. fiat/Z 151714711 $0M) y M 1 I w u nlzz Patented July 9, 1 946 DRAFT GEAR George E. Dath and Roland J. Olander, Chicago, Ill., assignors to W.- H. Miner, Inc., Chicago, 11]., a corporation of Delaware Application July l7, 1943, Serial No. 495,092

This invention relates to improvements in draft gears for railway cars.

One object of the invention is to provide a railway draft gear, comprising a friction shock absorbing mechanism, especially designed for absorbing shocks produced by a pulling or draft action applied to the coupler or drawbar of'a railway car. I

A more specific object of the invention is to provide a draft rigging for railway cars comprising a drawbar and a friction shock absorbing mechanism, especially designed to cushion the pulling shocks transmitted by the drawbar, wherein the friction shock absorbing mechanism includes a friction casing, friction shoes slidable within the casing, a central wedge spreading member cooperating with the shoes, and spring resistance means within the casing opposing inward movement of the shoes, and wherein the friction shock absorbing mechanism is actuated in draft by the drawbar which extends through the casing and has shouldered engagement with the wedge to force the latter inwardly of the casing, thereby spreading the shoes apart and moving the same inwardly of the casing opposed by the spring resistance, thus providing high combined spring and frictional resistance to provide the desired cushioning action.

Other objects of the invention will more clearly appear from the description and claims hereinafter-following.

. In the drawing forming a part of this specification, Figure 1 is a longitudinal sectional view, through the underframe structure of a railway car, at'one end thereof, illustrating our improvements in connection therewith. Figure 2 is an end elevational view, on an enlarged scale, of the structure shown in Figure 1, looking from right to left in said figure, the underframe structure of the car being omitted. Figure 3 is a vertical 7 Claims. (Cl. 21334) sectional view, corresponding substantially to the line 3--3 of Figure 2. Figure 4 is a view, similar to Figure 2, illustrating the manner of assembling the parts of the friction shock absorbing unit. Figure 5 is a view, similar to Figure 3, but taken on the line 5-5 of Figure 2, illustrating the manner of assembling the parts of the friction shock absorbing unit.

In said drawing, [0 indicates the usual end sill of the car underframe structure, and II one of the center sills. As will be understood by those skilled in this art, the usual underframe structure comprises two spaced center sills and these are fixed at their front ends to the end sill. Rearwardly or inwardly of the end sill, the underframe structure has a transverse connecting member I2 which extends between the two sills from one to the other, and has its opposite ends fixed thereto. The member l2 serves as the front stop of the draft rigging of the car and is reins forced by a heavy plate I 3 on the inner side thereof, which is preferably welded thereto. The end sill l0 and the member l2 are of channel-shaped cross section and are connected by top and bot! tom plates l4 and M, which are secured to the top and bottom flanges of said channel members. The drawbar of the car, which is indicated by 5, is of the type having a coupling hook at the outer end thereof for engagement with the coupling means of an adjacent car. The drawbar l5 has an enlarged head 16 at the outer end having the hook formed. thereon. The shank ll of the drawbar 15, which extends rearwardly from the head, is of cylindrical cross section, that is, in the form of a cylindrical bar or shaft. The usual nut I8 is threaded on the rear end of the shank I1. The drawbar I5 is accommodated for lengthwise sliding movement in aligned openings [9 and 20 in the end sill l0 and connecting member l2-l3. The head l6 of the drawbar is reduced in size-at the rear end thereof where it joins the cylindrical shank [1, thereby providing top and bottom shoulders 2 l-2l adapted to engage the front face of the end sill l0 and limit inward movement of the drawbar.

Our improvements, as shown in the drawing, comprise broadly a friction casing -A, a wedge block B, three friction shoes CC-C, and a spring resistance D.

As shown in Figure 1, the friction unit comprising the casing A, block B, shoes c-o c, and spring D, is disposed between the draft or center sills of the car in abutment with the front stop l2-l3. The shank I! of the drawbar 15 extends through the unit and actuates the same in draft action, as hereinafter pointed out. I

The friction casing A is in the form of a shell of hexagonal transverse cross section, open at one end, and closed at the other end by a transverse wall 22. As shown in Figure 1, the closed end of the casing A bears on the front stop '|2-l3 of the underframe of the car. The open end of the casing is thus presented at the rear or inner end of the draft rigging. The side walls of the casing. which are indicated by 23-23, are thickened at the open end of the casing, as indicated at 24, and present six fiat interior friction surfaces 2525 which converge inwardly of the casing, thereby providing a tapered friction shell portion 26 at the open end of the casing. At the open The wedge B is in the form of a block centrally recessed at the outer end, as indicated at 29, to

provide a seat for the nut N3 of the coupler shank l1. provided with three projectingwedge faces 30 of substantially V-shaped transvers'ehrosssection.

The wedge faces 30 are disposed symmetrically.

about the central longitudinal axis of the mechanism and converge inwardly'of the casing to ward said axis. with three radially projecting lugs 3I3l-3! which are alternated with the !-shaped wedge faces thereof. The lugs' 3I3|3I are located at the inner end of the wedge block and in the assembled condition of the mechanism are in longitudinal alignment with, the corresponding stops of the casing formed by the lugs 21 and shoulders 28, and are engaged therebetween so that inward movement of the wedge is'limited by engagement of the lugs 3| with the shoulders 28 and outward movement by engagement with the lugs 21. At the inner end, the block B is provided with a substantially flat transverse end face 32 which forms a spring seat. The block B has a central opening 33 therethrough adapted to accommodate the shank I1 of the drawbar H5. 'The walls of the opening are notched at diametri cally' oppositesides of the opening, as indicated at 34, to cooperate with a spanner, or similar tool,- used in assembling the mechanism.

"The friction shoes 0, which are three in numher, are of substantially V-shaped cross section, each shoe presenting a V-shaped wedge face 35 at the inner side thereof and a V -shaped friction surface 36 at the outer side. The friction shoes CC'C are alternated with the lugs 21-21--21 of the casing and have the V-shapedfriction surfaces thereof slidably engaged with the corresponding friction surfaces of thecasing', the V- shaped surface of each shoe engaging two adjacent surfaces 2525 of the casing. The V-shaped wedge faces 353535 of the shoes cooperate with the V-shaped wedge faces 303G-39 of the wedge block 13-. The wedge faces 353535 of the shoes are formed on lateral inward enlargements 31 on the shoes, the enlargement 31'of each shoe presenting a flat face 38 at the inner end thereof forming a spring seat.

" The springresistance lltvhi'ch is preferably under initial compression, is disposed within the casing A and comprises a relatively light inner coil 39 and a, heavier outer coil 4% The opposite ends of the outer coil it bear respectively on the inner side of the end wall 22 of the casing and the spring seats 38 of the shoes C, and the opposite ends'of the inner "coil bear, respectively, :o'n-is'aid wall 22 and the fiat end face 32 of the wedge block B.

V As clearly shown in Figures 1 and 2, the shank 11 of the drawbar extends through the casing A of the mechanism, the wall 22 of the casing being provided with a central opening 4| ther'ethrough to accommodate the shank of the drawbar. The

=drawbar shank extends through the opening ll,

At the sides thereof, the wedge is The block B is also provided 4 and shouldered against the bottom of said seat. The nut i8 is preferably secured against accldental removal by a cotter pin 42 extending through the end of the drawbar shank.

In assembling the mechanism, the parts are all placed within the casing A by being inserted throughthe open end thereof, the springs 39 and ddbeidgfirst placed in position "therein. The shoes CC--C are then placed on the spring 40 and forced inwardly to a predetermined extent,

so that when the wedge B is placed thereon and turned to the position shown in Figure 4, the lugs 3|--3 |3l thereof will clear and pass inwardly beyondthelugs 2121-21 of the casing when the Wedge. is pushed inwardly. The wedge is then placed in position on the inner spring and shoes, 2. spanner, or similar tool, being engaged within the opening 33 of said wedge block B and notches 3434 of said opening to hold the block against rotation. Whilethe shoes are being held in said predetermined inward position, the wedge is forcedinwardly and given a slight turn in contra clockwise direction, as viewed in Figure 4, to bring the lugs 3! in alignment with the lugs 21 and in back of the latter, as shownin Figure 2, and the pressure is then removed, permitting the mechanism to expand and assume the position shown in Figure 3 with the lugs 3| of the wedge block engaged with the lugs 21 of the casing. Outward movement of the Wedge is thus limited by, the lugs 21, the latter serving to hold the mechanism assembled. As will be evident, the interengaging arrangement of the V-shaped wedge faces of the wedge and shoes and V-shaped friction surfaces of the shoes and. casing interlock the parts against relative rotation, thus preventing accidental rotary displacement of the wedge from cooperative relation with the retaining lugs 21 of the casing.

In the operation of the mechanism when a pulling force is applied to the drawbar, the wedge B will be pulled inwardly of the casing in unison with the drawbar, thereby forcing the wedge inwardl of thecasing against the resistance of the spring 39. Due to wedging engagement between the wedge and shoes,the shoes are forced apart against the friction surfaces of the casing and carried inwardly along' said friction surfaces resisted by the spring 40. 'Iheresultant combined spring and frictional resistance produced by this action provides the desired high shock ab sorbing capacity. Compression of the 'mechanism is positively limited'by engagement ofthe lugs 3| of the block B with the stop shoulders of the casing A, thus preventing the wedge B from being drawn too far into the casing by the drawbar and protecting the springs against undue compression. When the actuating force is'reduced, the springs 39 and 40 restore all of the parts to normal position, outward movement of the wedge being limited by engagement of the 1118 3! thereof with the stop lugs 21 of the casing.

, We have herein shown and described what we now consider the'preferred manner of carrying out our invention, but the same is merely illustrative and we contemplate all changes and modifications that come within the scope of the claims appended hereto.

1. In a railway draft rigging for a railway car having a front stop, the combination with a friction casing having one end closed and the other end open, said closed end bearing on the front stop of the car; of friction shoes having sliding engagement with the interior walls of said casing;

spring means opposing inward movement of said shoes; a block having wedging engagement with the shoes; spaced inner and outer stops on the casing; projecting stop lugs on said block engageable with said inner and outer stops for limiting inward and outward movement of said wedge block; and a drawbar extending through said casing, spring means, and block and having shouldered engagement with the latter to pull the same inwardly of the casing in draft.

2. In a railway draft rigging for a railway car having a front stop, the combination with a friction casing open at one end and closed at the other end, said last named end bearing on said front stop of the car; of friction shoes having sliding engagement with the interior walls of said casing; a Wedge block having wedging engagement with the shoes; spaced inner and outer stops on the inside of the casing engageable with said wedge block limiting ment of said wedge block; a spring resistance within said casing comprising two coils respectively opposing inward movement of said wedge block and shoes; and a drawbar extending through said casing and wedge block and having shouldered engagement with the latter to pull the same inwardly of the casing in draft.

3. In a railway draft rigging for a railway car having a front stop, the combination with a friction casin open at one end and closed at the 1 l other, said casing having longitudinally disposed, inwardl converging, interior friction surfaces at said open end, said casing having the closed end there-of abutting said front stop; of a drawbar having an elongated shank extending said front stop and easing; friction shoes within the casing having friction surfaces of V-shaped, transverse cross section engaged with the V- shaped friction surfaces of the casing; a central wedge block mounted on said drawbar shank and having wedging engagement with the shoes, said shoes and block having interengaging wedge faces of V-shaped, transverse cross section; inner and outer stops on the interior of the casing; laterally projecting lugs on said wedge block engageable with said inner and outer stops for limiting inward and outward movement of said block; means on said drawbar shank having shouldered engagement with the wedge block for forcing the same inwardly of the casing when a draft force is applied to said drawbar; and spring means within the casing surrounding said drawbar shank and yieldingly opposing inward movement of said shoes and wedge block.

inward and outward movethrough 4. In a railway draft rigging for a railway car having a front stop, the combination with a friction casing open at one end, the other end of said casing being engageable with said stop, said casing having longitudinally extending, interior friction surfaces at said open end; of a central wedge block, a drawbar for actuating said wedge; a plurality of friction shoes having sliding frictional engagement with the friction surfaces of the casing and wedging engagement with said wedge block; spring resistance means yieldingly opposing inward movement of said wedge and shoes; and inner stop means on said casing with which the wedge block is directly engageable to limit inward movement of the latter.

5. In a railway draft rigging, the combination with a front stop; of a drawbar; a friction casing engageable with said front stop, said casing havinwardly converging, interior friction surfaces; a friction clutch actuated by said drawbar having sliding frictional engagement with the friction surfaces of the casing, said clutch including friction shoes and a central wedge block; interior stop shoulders on said casing with which said block has direct shouldered engagement to limit inward movement thereof; and spring means within the casing yieldingly opposing inward movement of said clutch.

6. In a railway draft rigging, the combination with a front stop; of a drawbar; a friction casing engageahle with said front stop, said casing havinwardly converging, interior friction surfaces; a friction clutch actuated by said drawand having sliding frictional engagement with the friction surfaces of the casing, said clutch including friction shoes and a central wedge block; interior stop shoulders on the casing; outstanding lugs on said wedge block engageable with said stop shoulders for limiting inward movement of the wedge block; and spring means yieldingly opposing inward movement of said clutch.

'7. In a railway draft rig ing, the combination with a front stop; of a drawbar; a friction casing having inwardly converging, interior friction surfaces; a friction clutch actuated by said drawbar and having sliding frictional engagement with the friction surfaces of the casing, said clutch including friction shoes and a central wedge block; radial stop lugs on said wedge block; interior stop shoulders on the casing with which said lugs are engageable for limiting inward movement of the wedge block; and spring means yieldingly opposing inward movement of said clutch.

GEORGE E. DA'II-I. ROLAND J. OLANDER. 

